You might experience that your anti-virus software detects COE as a possible threat. This is just a false postive and a known issue with modern anti-virus software. You can read more about it and how to resolve the issue here.
COE requires access rights to the directory where it is running, as it creates a log file next to the executable when launched.
java -jar coe.jar
This will print:
Now running on port 8082 Hit Enter to stop.
The COE responds to http so simply fetch the API documentation by:
curl -o api.pdf http://localhost:8082/api/pdf
Now the file api.pdf should be avaliable.
For convenience the latest documentation can also be found here